Switch



March 25, 1947.

R. T. CORNELIUS SWITCH Filed Oct. 28, 1943 2 Sheets-Sheet 1 March l25, 1947. R, T, QRNELlUs A 2,418,068

SWITCH Filed Oct. 28, 41942" 2 Sheets-Shed 2 u z; 4,5 e

s ..1 r.. ,s H lo l n? wam e w m n uz z @n n m .w w www v .1C u A Fl ...7 8 m w 9 lo h. um. :l4 nl .FU 4 .N lllln w R lo .1 0 ww M@ W. 7 i Y Z i 7 Z Nw 6 5%/ w i |l|8 l: A. 1 uw m., Y .7. Mm \\4 M M w 4 A. \\m.. M5 u nilo. :o Z l 4 i# b .1 nu 1/ M.. 4 Fl Z Mn. .75. d mu 4 7 lllL z f 4 4 R. .Q m?. .1 n u. e.. ,M LL 7m/f Patented Mar. 25, 1947- UNiTEDJs'rATEs PATENT OFFICE melma 'r. comsenuamnneapons. Mum.

My invention relates particularly to heavy duty snap' action switches in which the switch member is moved from either closing or opening position through an overcenter device.

An object of the invention resides in providing a small, compact and light switch capable of` carrying an appreciable current.

An object of the invention resides in providing a switch which will operate positively and without arcing, upon exteremely slow movement of the actuating member of the switch.d

Another object of the invention resides in providing a.switch which will maintain full contact pressure until actual opening of the switch occurs.

A still further object of the invention resides in providing a switch having an operating member and a switch member, and in providing means for causing said operating member to move in` opposite directions with a snap action and in further providing a lost motion connection be-v tween said switch member 4and operating member.

A still further object of the invention resides in providing an ear on one of the members and having an openingitherein and in forming a tongue on the other member adapted to be received in the opening and alternately engaging to electric switches, and

.switch in open position.

.In the use of the over-center type of electric switch. `considerable diiliculty has been encountered when the over-center device reaches dead center. With such devices, the switch member is connected to one of the members directly operated by the over-center device and when the over-center device reaches dead center, pressure upon the contacts is reduced and arcing occurs. This is'particularly true where the actuating means has a slow motion, such as a thermostat and in which' heavy current is being carried. Such switches, while the over-center device is on dead center.` are frequently operated prematurely by vibration or slight jar. The present invention overcomes this dimculty by providing a construction in which the switch member is not actuated until the over-center device is well past dead center.

My invention includes a base I0 constructed of insulating material and on which certain of the 'parts are mounted. This base is rabbeted along the edges thereof, as indicated at II, to receive a cover I2 for the mechanism of the switch. The cover I2 has a top I3, side walls .Il and I5 and end walls I6 and I1, said side and arm .24 which all extend longitudinally of theA base I0. These members are all constructed of resilient or spring material and have overlying parts 25. 26 and 21 which are all clamped tonovel combination and arrangement of parts and taken on line 3-3 of Fig. 1.

Fig. 4 is a view similar to Fig. 1 taken through gether on a pad 28 formed on the base I0. For

this purpose, two screws 29 are employed which pass through the parts 25, 26 and 21 of the members 22, ila and 2l and which are screwed into 7 ananas means of a similar connecting part 35. The part rent-carrying yoke 31. The two contacts 36 are adapted -to engage fixed contacts 38 which are imbedded in the base I and insulated from one another. These contacts have threaded holes 4| adapted to receive binding screws 42 by means of which conductors may be connected to the said contacts. VThe switch member 22 operates between the contacts 38 and a xed stop 43 formed on the inner surface of the top I3 of cover I2. The flexure in the switch member 22 is such that whenl in its free position, the contacts 36 are urged against the contacts 38 with suicient pressure to prevent arcing.

The operating member 23 is similarly constructed with reference to the switch member 22 and has an opening 44 therein which forms the said member with two longitudinally extendingI bars 45 connected at their outer ends by a connecting part 46 and at their inner ends by the part 21, previously referred to. Extending downwardly from the bars 45 at their outer edges are flanges 41 which extend from the part 46 to within a short distance of the part 26. These flanges prevent bending of the bars throughout the major portion throughout the length thereof and limit the bending of said bars to a locality indicated at 48 in close proximity to the part 26. The-member 23 is situated entirely below the member 22 and is at all times so disposed.

The member 23 falls short of the outer end of the opening 32 in the member 22 and has an ear I extendingoutwardly therefrom and through saidopening. This ear has an aperture 52 in it which provides two abutments 53 and 54 formed with facing surfaces spaced from one another. Atongue 55 formed on the part 35 of member 22 extends into this aperture. The opposite sides of this tongue provide oppositely facing surfaces adapted to be alternately engaged by the surfaces of the abutments 53 and 54. Member 22 is operated by member'23 by means of these surfaces.. The spacing of the abutments 53 and 54 is'sufliciently great to produce a lost motion between the po-acting parts, so that memwith the stop 63.

ing part of the member 23.V Operating between these portions of the members 23 and 24 is an over-center device 65 which consists of a c-shaped spring 66 having sockets 61 and '88' formed at its ends. These sockets engage fulcrums 1I and 12 formed on the connecting part 46 of the member 23 at its inwardly facing edges l and formed on the blade 58 of the member 24 at its-outwardly facing edge. The fulcrum 1I is arcuate, as best shown in Fig. 2, to provide a single-point Acontact intermediate the lateral edges of the spring 66. The fulcrum 12 is rement of the member 24 with which it is associated.

The operation of the invention -is as follows: In 'normal position, the member 24 is in its upward position with the blade in engagement This throws the fulcrum above dead center, causing the member 23 to be urged downwardly. Member 22, through its own resiliency, is urged downwardly, bringing the contacts 3B rmly against the contact 38. In such position, the engaging surface ofthe abutment 53 bears against the upper surface of the tongue 55. The switch is then closed. When the button 58 is depressed through engagement with the end 62 of the stem 59, member 24 is lowered. When the blade 58 reaches a coplanar relationship with reference to the bars 45 of the member 23, downber 23 may have considerable movement before l the member 22 is operated thereby.'

'I'he actuating member 24 consists of a spring blade 58, considerably shorter than the member 23 and operating entirely within the two openings 32 and 44 of the members 22 and 23, respectively. The member 24 is constructed with flanges 56 similar to the flanges 41 which extend from the end of said member and to within a short distance of the part 26 of said member. These flanges stiften the said member and localize the flexure to a locality indicated at 51 in proximity to the part 26. The blade 58 is normally flexed, so that the same has a tendency to move upwardly and bring the switch member 22 into closing position, as will be hereinafter more fully described.

The member 24 is actuated by means of an actuating button 58 which is disposed on a stem 59 slidably mounted in a hole .6I drilled -in the top I3 of cover I2. When the protruding end 62 of this stem is depressed, the button 58 engages the blade 58 and moves the member 24 downwardly. 'I'he blade 58 operates between two stops 63 and 64 formed on the cover I2 and base I 0, respectively.

It will be noted that the outer end of the blade ward pressure is no longer exerted by the said member on the member 22. However, the said member has enough resiliency of its own to maintain suilicient pressure on the contact to prevent arcing. The parts of the over-center device are now at dead center.

center and the spring 66 exerts a pressure on the member 23 tending to move the same upwardly. The member 23 now gradually commences to move upwardly as the'member 24 continues to move downwardly. If the actuation of the button 58 is very slow, the movement of the member 23 is likewise slow and at the beginning of its upward movement, it has little or no upwardly exerted force. During this period of the movement of the member 23, the 'ear 5I 4moves relative to the tongue 55 without engaging the same. D uring such movement, the abutment 53 recedes from the upper surface of the tongue 55 and the abutment 54 approaches the lower surface of said tongue. During such movement, member 22 is free from member 23. When the over-center device is well past dead center and the member-23 is capable of exerting appreciable force on the member 22,' abutment 54 engages tongue 55 and moves the member 22 upwardly with a snap action. When the pressure on the button 58 is released, the resiliency of the member 24 moves the same upwardly and causes reverse movement of the parts. Again lost motion occurs between the movements of the member 23 past dead center, so that the member 22 is not moved toward switch-closing position until after the over-center device is well past dead center.

`The advantages of my invention are manifest. With my invention, the switch member is not operated until the operating member has suffi- As the blade 50 continues to move downwardly, the member 24 passes dead cient force to positively and quickly move the same. Thus, arcing at the contacts is prevented. My switch may be constructed in an inexpensive manner and is capable of handling an appreciable amount of current. The switch is extremely sensitive and can be made to operate with a small movement of the actuating member. My improved switch is particularly adapted to be used with slowly moving actuatingV devices, such as thermostats and the like, and will operate both in opening and closing with a positive snap action. My improved switch will not be aiected by vibrations when the over-center device is substantially at dead center, so that premature operation of the switchvis prevented.

Changes in the specific form of my invention, as herein described, may be made within the scope of what is claimed without departing from the spirit of my invention.

Having described my invention, what I claim as new and desire to protect by Letters Patent 1. In a switch, a movable switch arm consisting of spaced bars and connecting parts at the ends thereof, an operating member constructed with spaced bars and connecting parts at the ends thereof, and an actuating member constructed in the form of a blade, said members being all secured together in proximity to one another at one end of each member and being free to move at the other end, said blade being movable in the space between the bars of both said switch member and operating member, contact means at the free end of the switch member, a spring operating between the free vends of the operatingY member and the actuating member and serving as an over-center device for procuring snap i another and extending generally in the same diaction of the operating member upon movement u of the actuating member and a lost motion connection between said switch member and said operating member at the free ends thereof.

2 In a switch, a movable switch arm consisting of spaced bars and connecting parts at the ends thereof, an operating member constructed with spaced bars and connecting parts at the ends thereof, an actuating member constructed in the form of a blade, said members being all secured together in proximity to one another at one end of each member and being free tomove at the other end, said blade beingmovable in the space between the bars of both said switch member and operating member, contact means at the free end of the switch member, a spring operating between the free ends of the operating member and the actuating member and serving as an over-center device for procuring snap action of the operating member upon movement of theactuating member, a pair of spaced abutments on said switch member having surfaces and a pair of spaced surfaces on said operating member, one pair of surfaces facing in opposite directions, the other pair of surfaces facing one another and being spaced apart a distance greater than the other surfaces to receive the same therebetween. i

3. In a switch. an elongated switch member. an elongated operating member and an elongated rection, said members being each mounted for lswinging movement about one end thereof, a

snap action device acting between the free ends of the actuating member and the operating member, and a lost motion device acting between the free ends of the operating member and the switch member.

4. In a switch, an elongated switch member, an elongated operating member and an elongated actuating member all juxtaposed relative to one another and extending generally in the same direction, said members being constructed of resilient material and being in the form of leaf springs, a base, means for attaching each of said members at one end to said base to support said members for swinging movement, a snap action device, acting between the free ends of the ac-` tuating member and the operating member, and a lost.motion device acting between the free ends of the operating member and the switch member.

5. In a switch, a movable switch member con-- sisting of spaced bars and connecting parts at the ends thereof, an operating member constructed with spaced bars and connecting parts at the ends thereof, and an actuating member to which motion is applied from without the switch and constructed in the form of a blade, said members being al1 secured together in proximity to one another at one end of each member and being free to move at the other end, said actuating member being movable in the yspace between the bars of both said switch member and operating member, contact means at the free end of the switch member, a spring operating between the free. ends of the operating member and the actuating member and serving as an over-center device for procuring snap action of the operating member upon movement of the actuating member, said operating member and said switch member having juxtaposed parts, an ear projecting outwardly from one of said parts and extending in the direction of movement thereof and having an aperture therein provided with spaced edges forming abutments, a tongue on the other of said parts extending in the direction thereof and received within said aperture, said tongue being alternately engaged by said abutment to form a lost-motion connection between said switch member and the operating member at the free ends thereof.

RICHARD T. CORNELIUS.

REFERENCES CITED The following references are of record in the file of this patent:

UNrrEp STATES PATENTS 

